1. Field of Invention
The invention relates to a print head component and the manufacturing method thereof. In particular, the invention relates to a component for the inkjet print head that requires a low production costs and the manufacturing method thereof.
2. Related Art
The print head is a key component of inkjet printers. The assembly of current print heads is usually done by first making the orifice plate and the print head chip. Afterwards, a photosensitive adhesive is coated on the chip. Ink chambers and ink supply channels are then formed on the adhesive by photolithography. The orifice plate and the chip are aligned and attached together with the photosensitive adhesive. Finally, tape automated bonding (TAB) leads are aligned and attached onto the electrical signal pads of the chip using high temperature and pressure.
The signal pads of the print head chip are combined with the wire pads of a substrate using aligned embossing of the inner leads. This requires the use of inner lead bonding (ILB) equipment in semiconductor technology. During packaging, the signal pads of the print head chip and the wire pads on the substrate have to be aligned accurately. The wire pads are then connected to the signal pads by embossing. The welded region is filled with glue to increase its reliability. As this procedure requires high precision and has certain difficulty, conditions in the manufacturing process greatly affect the quality of the packaged elements. On the other hand, the orifice plate used in the existing technology is made by electroforming. First, an electroplating solution has to be precisely prepared. A good electroforming quality can be obtained only after long time experiment and calibration. Therefore, it is very hard to control the size, roundness, and thickness of the orifices in such batch produced orifice plates using this method. Moreover, the bonding strength of the metal orifice plate and the inkjet chip may be lowered with time because of the erosion of the ink inside the ink chamber. This will eventually result in local delamination.
One may also form orifices on the TAB by laser ablation. With reference to the U.S. Pat. No. 5,305,015, the manufacturing process starts by forming transmission holes on a TAB substrate. Signal wires are then defined by electroforming or copper foil attaching. Afterwards, a laser beam is shined and focused on the substrate to make an orifice. After a cleaning process, it is combined with the chip by embossing, thus completing the print head chip packaging. However, a laser is used to make orifices individually in this method. There are three hundred nozzles on a high resolution inkjet print head at least. Therefore, it takes a long time and the equipment is expensive. Moreover, the high temperature produced in the process often deforms the borders of the orifices. If one wants to make orifices of different sizes, different lenses have to be used to focus the laser beam. It is also very hard to remove the debris' around the orifices produced in the lasing process.